The majority of the following videos come from a 2001 performance on the Later With Jools Holland show. This was during the Kid A – Amnesiac period which featured the band exploring the avant garde. Traditional arrangements (vocal+bass+guitars+drums) were out in favor of brass sections, digital effects and electronic instruments such as the Ondes Martinot (the theremin sounding thingy played by Jonny Greenwood).
The last video is something I’ve only recently found. It is a 2001 performance of one of Radiohead’s masterpieces “How to Disappear Completely” from French television. This version, however, features an arrangement by not one, not two, but three Ondes Martinot players. It is one of the most beautiful performances of anything that I’ve ever heard.